Electric motor and electric power steering system

Abstract

The application provides an electric motor and an electric power steering system, and relates to the technical field of electric motors.The electric motor comprises a rotor, a stator and a permanent magnet.The rotor comprises a rotor core and the permanent magnet, and the permanent magnet is attached to the outer surface of the rotor core.The stator is sleeved on the circumferential side of the rotor, and comprises a stator yoke and a plurality of stator teeth.The plurality of stator teeth are distributed along the circumferential direction of the stator yoke, one end of each stator tooth is connected with the stator yoke, and the other end of the stator tooth extends along the radial direction of the stator.In the radial direction of the stator, the thickness of the stator yoke is h, and in the circumferential direction of the stator, the width of the stator tooth is t, and the relationship between h and t satisfies the following relationship: 1.5 <= t / h <= 1.7.The application can optimize the size of the stator, improve the magnetic saturation of the stator, improve the torque performance and efficiency of the electric motor using the stator, and reduce the copper consumption of the stator, so as to improve the performance-price ratio of the electric motor.

Description

Technical Field

[0001] This application relates to the field of electric motor technology, and more specifically, to an electric motor and an electric power steering system. Background Technology

[0002] Currently, with the promotion and increasing demand for new energy vehicles, the requirements for intelligent and energy-efficient electronic EPS (Electric Power Steering) systems are also gradually increasing.

[0003] In related technologies, how to optimize the dimensions of the stator structure of an electric motor and improve its torque performance and efficiency is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] This application aims to solve at least one of the technical problems existing in the prior art or related art. To this end, the first aspect of this application proposes an electric motor.

[0005] The second aspect of this application proposes an electric power steering system.

[0006] In view of the above, a first aspect of this application provides an electric motor comprising: a rotor, the rotor including a rotor core and a permanent magnet, at least a portion of the permanent magnet being disposed in contact with the outer surface of the rotor core; and a stator, the stator being sleeved on the periphery of the rotor, the stator including a stator yoke and a plurality of stator teeth, the plurality of stator teeth being distributed circumferentially along the stator yoke, one end of each stator tooth being connected to the stator yoke, and the other end of the stator tooth extending radially along the stator; wherein, in the radial direction of the stator, the thickness of the stator yoke is h, and in the circumferential direction of the stator, the width of the stator teeth is t, and h and t satisfy the following relationship: 1.5≤t / h≤1.7.

[0007] In this technical solution, the electric motor is used in EPS (Electric Power Steering). The electric motor includes a stator and a rotor. The stator is sleeved on the periphery of the rotor, that is, the rotor passes through the inside of the stator and passes through the axis of the stator. The rotor in the electric motor is a surface-mounted rotor, that is, the permanent magnet is attached to the rotor core.

[0008] In this technical solution, the stator includes a stator yoke and a stator tooth. The stator tooth is disposed on the stator yoke, and there are multiple stator teeth. The multiple stator teeth are disposed on the inner side of the stator yoke and distributed circumferentially along the stator yoke.

[0009] In this technical solution, the stator yoke thickness is defined as h, which is the thickness dimension of the stator yoke in the radial direction of the stator. Specifically, the yoke thickness h is the maximum thickness of the stator yoke in the radial direction of the stator. The stator tooth width is defined as t, which is the width dimension of the stator tooth in the circumferential direction of the stator. The tooth width is the maximum width of the stator tooth in the circumferential direction of the stator. The value range of the ratio t / h of the yoke thickness h and the tooth width t is set to be greater than or equal to 1.5 and less than or equal to 1.7.

[0010] Specifically, by setting the thickness of the stator yoke to be less than the width of the stator teeth, and designing the width of the stator teeth to be greater than 1.5 times the thickness of the stator yoke and less than 1.7 times the thickness of the stator yoke, the size of the stator can be optimized, thereby improving the magnetic saturation of the stator and reducing the amount of copper used in the stator.

[0011] In this application's technical solution, the stator includes a stator yoke and stator teeth. Multiple stator teeth are disposed on the stator yoke, and the stator teeth extend radially towards the inner side of the stator yoke. The numerical relationship between the thickness of the stator yoke and the width of the stator teeth is defined. By limiting the width of the stator teeth to a range greater than 1.5 times the thickness of the stator yoke and less than 1.7 times the thickness of the stator yoke, the stator dimensions can be optimized, the stator's magnetic saturation can be improved, the torque performance and efficiency of the motor using this stator can be improved, and the amount of copper used in the stator can be reduced, thereby improving the motor's cost-effectiveness.

[0012] In some technical solutions, optionally, the stator yoke and two adjacent stator teeth enclose each other to form a stator slot, the number of stator slots being Z. The stator also includes a pole shoe, which is connected to the other end of the stator teeth. The distance from the axis of the stator to the pole shoe is D1. Z, D1 and t satisfy the following relationship: 0.58≤Z×t / (π×D1)≤0.63.

[0013] In this technical solution, the stator includes a stator slot, which is an empty slot formed by the stator yoke and the stator teeth. The stator slot is used to accommodate the coil when the stator teeth are wound. Specifically, one stator slot is formed by the stator yoke and two adjacent stator teeth. The bottom surface of the stator slot is the inner surface of the stator yoke where the stator teeth are located, and the bottom surface of the slot is located within the stator slot.

[0014] In this technical solution, the two ends of the stator teeth are connected to the stator yoke and the pole shoe respectively. The number of pole shoes is the same as the number of stator teeth. The pole shoes are arranged in a one-to-one correspondence with the stator teeth. The pole shoes are located at the end of the stator teeth that extends into the stator yoke.

[0015] It should be noted that D1 is the inner diameter of the stator, which is defined as the distance between the axis of the stator and the pole shoe.

[0016] In the technical solution of this application, by limiting the inner diameter D1, tooth width t and number of stator slots Z to satisfy the following relationship: 0.58≤Z×t / (π×D1)≤0.63, the magnetic saturation of the stator can be further improved, thereby ensuring that the motor using this stator has high torque performance and efficiency.

[0017] In some technical solutions, optionally, the distance from the axis of the stator to the outer side of the stator yoke is D2, and the outer side is the side away from the stator teeth. D1 and D2 satisfy the following relationship: 0.576≤D1 / D2≤0.60.

[0018] In this technical solution, the stator yoke includes an inner side and an outer side. The inner side of the stator yoke is the side where the stator teeth are located, and the outer side of the stator yoke is the side where the stator teeth are not connected, that is, the side away from the stator teeth. D2 is the outer diameter of the stator, that is, the distance from the axis of the stator to the outer side of the stator yoke is defined as the outer diameter of the stator.

[0019] In the technical solution of this application, by limiting the range of the ratio of the inner diameter to the outer diameter of the stator, D1 / D2, to be greater than or equal to 0.576 and less than or equal to 0.60, the stator has a larger ratio, reducing the outer diameter of the stator and thus reducing the amount of copper used in the stator. Therefore, the production cost of the motor using this stator is reduced, making the motor more cost-effective.

[0020] In some technical solutions, optionally, the stator stack thickness is T, and the remanence of the permanent magnet is Br; T, Br, D1 and D2 satisfy the following relationship: 35≤T×Br×D1 / D2≤40.

[0021] In this technical solution, the stator is used in the EPS motor, which also includes a rotor, on which permanent magnets are installed.

[0022] It should be noted that the stator stack thickness refers to the stator stack thickness. The greater the stator stack thickness, the greater the power and torque of the motor, but at the same time, the material cost and losses of the iron core and coil will also increase.

[0023] It should be noted that the remanence of a permanent magnet refers to the magnetic field strength that the permanent magnet retains after being magnetized during motor operation, even when the applied external magnetic field is relatively small. The unit of remanence for an electromagnetic magnet is T. Permanent magnets are made of permanent magnet materials. After being saturated magnetized and the external magnetic field is removed, these materials can maintain stable magnetism for a long time. This helps to establish a constant magnetic field in the air gap, thus affecting the operating stability and efficiency of the motor.

[0024] In the technical solution of this application, by limiting the numerical relationship between the residual magnetism Br of the permanent magnet, the stack thickness T of the stator, and the inner diameter D1 and outer diameter D2 of the stator, and by making T, Br, D1 and D2 satisfy the relationship 35≤T×Br×D1 / D2≤40, it is possible to ensure that the motor using the stator has a high torque, and to ensure the rationality of the electromagnetic load of the motor, thereby improving the torque output capability of the motor.

[0025] In some technical solutions, T, D1, and D2 may optionally satisfy the following relationship: 0.25 ≤ T × D1 / (D2) 2 ≤0.35.

[0026] In the technical solution of this application, by further limiting the dimensions of the stator stack thickness T and the stator inner diameter D1 and outer diameter D2, the stator stack thickness T, inner diameter D1, and outer diameter D2 satisfy 0.25≤T×D1 / (D2). 2 The formula with a value of ≤0.35 allows for the design of stator dimensions without considering the residual magnetism of permanent magnets, ensuring the rationality of the electromagnetic load of the motor and improving the torque output capability of the motor.

[0027] In some technical solutions, optionally, the maximum distance from the axis of the stator to the bottom surface of the stator slot is d, where d, h, D1 and Br satisfy the following relationship: (2×d-D1)Br / h≥7.

[0028] In the technical solution of this application, the maximum distance from the axis of the stator to the bottom surface of the stator slot is defined as d, and the thickness of d, the thickness of the stator yoke h, the inner diameter of the stator D1, and the remanence of the permanent magnet are limited. Furthermore, d, h, D1, and Br are limited to satisfy the relationship (2×d-D1)Br / h≥7, thereby improving the magnetic saturation of the stator yoke, further improving the rationality of the electromagnetic load of the stator, and thus further improving the torque output capability of the motor using the stator of this application.

[0029] In some technical solutions, the bottom surface of the stator slot optionally includes a first arc segment, a second arc segment, and a planar segment, wherein, in the circumferential direction of the stator, the planar segment is located between the first arc segment and the second arc segment.

[0030] In this technical solution, the bottom surface of the stator slot is designed as a three-section structure, comprising a first arc-shaped section, a second arc-shaped section, and a planar section located between the first and second arc-shaped sections. In the circumferential direction of the stator, the first and second arc-shaped sections are located on either side of the planar section.

[0031] Specifically, the first and second arc-shaped sections are positioned near the stator teeth at both ends of the stator slots. When winding the stator teeth, this helps to increase the full slot ratio of the winding and makes the stator winding more neat. Furthermore, by setting the bottom of the slot between the first and second arc-shaped sections as a flat section, the magnetic saturation of the stator yoke can be further improved.

[0032] In the technical solution of this application, by designing the bottom surface of the stator slot as a three-section structure and setting the planar section between the first arc section and the second arc section, the stator winding fullness and winding neatness can be improved, as well as the magnetic saturation of the stator yoke can be improved.

[0033] In some technical solutions, optionally, the number of stator slots Z is 12 to 48, the number of rotor poles is P, and the value of Z / P ranges from 6 / 5 to 3 / 2.

[0034] In the technical solution of this application, the number of stator slots Z in the stator is limited to 12 to 48, and the ratio of the number of stator slots Z to the number of rotor poles P is limited to 6 / 5 to 3 / 2, which can improve the magnetic saturation of the stator and improve the torque output capability of the motor using the stator of this application.

[0035] In some embodiments, the number of permanent magnets may be multiple, and the multiple permanent magnets are distributed at intervals along the circumference of the rotor core.

[0036] The rotor core has multiple grooves on its surface, with a groove between any two adjacent permanent magnets; or the rotor core has multiple limiting protrusions on its periphery, with a limiting protrusion between any two adjacent permanent magnets.

[0037] In this embodiment, the rotor is a surface-mount rotor, and multiple permanent magnets are mounted on the periphery of the rotor core in a bonded manner, with any two adjacent permanent magnets spaced apart on the periphery of the rotor core. Specifically, the multiple permanent magnets are evenly distributed on the periphery of the rotor core.

[0038] Specifically, the rotor core has multiple grooves on its periphery, and these grooves are located between any two adjacent permanent magnets; that is, at least one groove is provided between any two adjacent permanent magnets. These grooves increase the surface area of ​​the rotor core, forming airflow channels on its surface, which effectively improves the cooling effect of the rotor core. Furthermore, the grooves optimize the magnetic circuit distribution of the rotor, helping to reduce harmonics generated during rotor core operation, lowering the noise generated by the motor, and also reducing the material used in the rotor core, thus reducing its weight and saving costs.

[0039] Specifically, the rotor core has multiple limiting protrusions on its circumference, and these protrusions are located between two adjacent permanent magnets; that is, at least one limiting protrusion is provided between any two adjacent permanent magnets. These limiting protrusions act as a limit to the permanent magnets attached to the rotor core in the circumferential direction, improving the stability of the permanent magnets on the rotor core and thus enhancing the stability of the motor operation.

[0040] The second aspect of this application proposes an electric power steering system for use in a vehicle. The electric power steering system includes an electric motor as described in any of the above technical solutions, and therefore has all the beneficial effects of the electric motor as described in any of the above technical solutions, which will not be described in detail here.

[0041] Additional aspects and advantages of this application will become apparent in the following description or may be learned by practice of this application. Attached Figure Description

[0042] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0043] Figure 1 This illustration shows one of the structural schematic diagrams of the electric motor provided in some embodiments of this application;

[0044] Figure 2 This is a second schematic diagram of the structure of the electric motor provided in some embodiments of this application;

[0045] Figure 3 This illustration shows one of the structural schematic diagrams of the stator provided in some embodiments of this application;

[0046] Figure 4 This is a second schematic diagram of the stator structure provided in some embodiments of this application;

[0047] Figure 5 The diagram shows a schematic representation of the stator slot provided in some embodiments of this application;

[0048] Figure 6 The following are schematic diagrams illustrating the structure of the stator teeth and pole shoes provided in some embodiments of this application;

[0049] Figure 7 The present application provides schematic diagrams of the rotor core structure in some embodiments.

[0050] Figure 8 The present application provides schematic diagrams of the structure of vehicles according to some embodiments;

[0051] Figure 9 A comparative diagram of torque, cost-effectiveness, and cost provided in some embodiments of this application is shown.

[0052] in, Figures 1 to 8 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0053] 100 Stator, 110 Stator yoke, 111 Outer surface, 120 Stator tooth, 130 Pole shoe, 131 First shoe surface, 132 Second shoe surface, 133 Third shoe surface, 140 Stator slot, 141 Slot bottom surface, 1411 First arc segment, 1412 Second arc segment, 1413 Planar segment, O Stator axis, 200 Motor, 210 Rotor, 211 Rotor core, 212 Permanent magnet, 213 Groove, 214 Limiting protrusion, 300 Electric power steering system, 400 Vehicle. Detailed Implementation

[0054] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0055] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0056] The following reference Figures 1 to 9 This application describes an electric motor and an electric power steering system according to some embodiments.

[0057] Figure 1 This illustration shows one of the structural schematic diagrams of the electric motor provided in some embodiments of this application. Figure 2 The second schematic diagram of the structure of the electric motor provided in some embodiments of this application is shown. Figure 3 This illustration shows one of the structural schematic diagrams of the stator provided in some embodiments of this application; Figure 4 This is a second schematic diagram of the stator structure provided in some embodiments of this application; Figure 5 The following are schematic diagrams of the stator slot structure provided in some embodiments of this application, such as... Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5As shown, the motor 200 includes: a rotor 210, which includes a rotor core 211 and a permanent magnet 212, with at least a portion of the permanent magnet 212 attached to the outer surface of the rotor core 211; and a stator 100, which is sleeved on the periphery of the rotor 210. The stator 100 includes a stator yoke 110 and a plurality of stator teeth 120, which are distributed circumferentially along the stator yoke 110. One end of each stator tooth 120 is connected to the stator yoke 110, and the other end of the stator tooth 120 extends radially along the stator yoke 110. The thickness of the stator yoke 110 is h in the radial direction of the stator 100, and the width of the stator tooth 120 is t in the circumferential direction of the stator 100. h and t satisfy the following relationship: 1.5 ≤ t / h ≤ 1.7.

[0058] In this embodiment, the motor 200 is applied to EPS (Electric Power Steering). The motor 200 includes a stator and a rotor 210. The stator is sleeved on the periphery of the rotor 210, that is, the rotor 210 passes through the inside of the stator and passes through the axis of the stator. The rotor 210 in the motor 200 is a surface-mounted rotor 210, that is, the permanent magnet 212 is attached to the rotor core 211.

[0059] For example, the motor 200 also includes a shaft that is fixedly connected to the rotor core 211.

[0060] In this embodiment, the stator 100 includes a stator yoke 110 and a stator tooth 120. The stator tooth 120 is disposed on the stator yoke 110. There are multiple stator teeth 120, which are disposed on the inner side of the stator yoke 110 and distributed circumferentially along the stator yoke 110.

[0061] For example, the stator yoke 110 and the stator tooth 120 are integrally formed, and the stator yoke 110 and the stator tooth 120 are made of copper.

[0062] In this embodiment, the yoke thickness of the stator 100 is defined as h, which is the thickness dimension of the stator yoke portion 110 in the radial direction of the stator 100. Specifically, the yoke thickness h is the maximum thickness of the stator yoke portion 110 in the radial direction of the stator 100. The tooth width of the stator 100 is defined as t, which is the width dimension of the stator tooth portion 120 in the circumferential direction of the stator 100. The tooth width is the maximum width of the stator tooth portion 120 in the circumferential direction of the stator 100. The value range of the ratio t / h of the yoke thickness h and the tooth width t is set to be greater than or equal to 1.5 and less than or equal to 1.7.

[0063] Specifically, by setting the width of the stator tooth portion 120 to be greater than the thickness of the stator yoke portion 110, and designing the width of the stator tooth portion 120 to be greater than 1.5 times the thickness of the stator yoke portion 110 and less than 1.7 times the thickness of the stator yoke portion 110, the dimensions of the stator 100 can be optimized, thereby improving the magnetic saturation of the stator 100 and reducing the amount of copper used in the stator 100.

[0064] like Figure 3 As shown, arrow A indicates the radial direction of stator 100, and arrow B indicates the circumferential direction of stator 100.

[0065] In this embodiment, the stator 100 includes a stator yoke 110 and stator teeth 120. Multiple stator teeth 120 are disposed on the stator yoke 110, and the stator teeth 120 extend radially toward the inner side of the stator yoke 110. The numerical relationship between the thickness of the stator yoke 110 and the width of the stator teeth 120 is defined. By limiting the width of the stator teeth 120 to a range greater than 1.5 times the thickness of the stator yoke 110 and less than 1.7 times the thickness of the stator yoke 110, the dimensions of the stator 100 can be optimized, improving the magnetic saturation of the stator 100, enhancing the torque performance and efficiency of the motor 200 using this stator 100, and reducing the amount of copper used in the stator 100, thereby improving the cost-effectiveness of the motor 200.

[0066] Figure 5 The diagram shows a schematic representation of the stator slot provided in some embodiments of this application. Figure 6 The following are schematic diagrams illustrating the structure of the stator teeth and pole shoes provided in some embodiments of this application, such as... Figures 1 to 6 As shown, in some embodiments, optionally, the stator yoke 110 and two adjacent stator teeth 120 enclose a stator slot 140, the number of stator slots 140 is Z, and the stator 100 further includes a pole shoe 130, the pole shoe 130 being connected to the other end of the stator teeth 120; the distance from the axis O of the stator 100 to the pole shoe 130 is D1, and Z, D1 and t satisfy the following relationship: 0.58≤Z×t / (π×D1)≤0.63.

[0067] In this embodiment, the stator 100 includes a stator slot 140, which is an empty slot formed by the stator yoke 110 and the stator teeth 120. The stator slot 140 is used to accommodate the coil when the stator teeth 120 are wound. Specifically, one stator slot 140 is formed by the stator yoke 110 and two adjacent stator teeth 120. The bottom surface 141 of the stator slot 140 is the inner side surface of the stator yoke 110 where the stator teeth 120 are located, and the bottom surface 141 is located within the stator slot 140.

[0068] In this embodiment, the two ends of the stator tooth 120 are connected to the stator yoke 110 and the pole shoe 130, respectively. The number of pole shoes 130 is the same as the number of stator teeth 120. The pole shoes 130 are arranged in a one-to-one correspondence with the stator teeth 120. The pole shoes 130 are located at the end of the stator tooth 120 that extends into the stator yoke 110.

[0069] For example, the stator teeth 120, stator yoke 110 and pole shoes 130 are integrally formed, and the stator teeth 120, stator yoke 110 and pole shoes 130 are all made of copper.

[0070] It should be noted that D1 is the inner diameter of stator 100, that is, the distance between the axis O of stator 100 and pole shoe 130 is defined as the inner diameter.

[0071] For example, the pole shoe 130 adopts a multi-segment structure, including a first pole shoe surface 131, a second pole shoe surface 132 and a third pole shoe surface 133. The second pole shoe surface 132 is located between the first pole shoe surface 131 and the third pole shoe surface 133. The second pole shoe surface 132 is a circular arc structure with a diameter equal to the inner diameter D1 of the stator 100. The distance between the first pole shoe surface 131 and the third pole shoe surface 133 and the center of the circle is greater than or equal to the inner diameter D1 of the stator 100.

[0072] In this embodiment of the application, by limiting the inner diameter D1, tooth width t and number of stator slots Z of stator 100 to satisfy the following relationship: 0.58≤Z×t / (π×D1)≤0.63, the magnetic saturation of stator 100 in motor 200 can be further improved, thereby ensuring that motor 200 using stator 100 has high torque performance and efficiency.

[0073] like Figures 1 to 6 As shown, in some embodiments, optionally, the distance from the axis O of the stator 100 to the outer side 111 of the stator yoke 110 is D2, and the outer side 111 is the side away from the stator tooth 120. D1 and D2 satisfy the following relationship: 0.576≤D1 / D2≤0.60.

[0074] In this embodiment, the stator yoke 110 includes an inner side and an outer side 111. The inner side of the stator yoke 110 is the side where the stator teeth 120 are located, and the outer side 111 of the stator yoke 110 is the side not connected to the stator teeth 120, that is, the side away from the stator teeth 120. D2 is the outer diameter of the stator 100, that is, the distance from the axis O of the stator 100 to the outer side 111 of the stator yoke 110 is defined as the outer diameter of the stator 100.

[0075] In this embodiment of the application, by limiting the range of the ratio D1 / D2 of the inner diameter to the outer diameter of the stator 100 to be greater than or equal to 0.576 and less than or equal to 0.60, the stator 100 has a larger ratio, reducing the outer diameter of the stator 100 and thus reducing the amount of copper used in the stator 100. Therefore, the production cost of the motor 200 using this stator 100 is reduced, making the motor 200 more cost-effective.

[0076] like Figures 1 to 6 As shown, in some embodiments, optionally, the stack thickness of stator 100 is T, and the remanence of permanent magnet 212 is Br; T, Br, D1 and D2 satisfy the following relationship: 35≤T×Br×D1 / D2≤40.

[0077] In this embodiment, the stator 100 is applied to the EPS motor 200, which also includes a rotor 210, on which a permanent magnet 212 is provided.

[0078] It should be noted that the stacking thickness of stator 100 refers to the stator stacking thickness of stator 100. The greater the stacking thickness of stator 100, the greater the power and torque of motor 200 will be, but at the same time, the material cost and losses of iron core and coil will also increase.

[0079] It should be noted that the remanence of the permanent magnet 212 refers to the magnetic field strength retained by the permanent magnet 212 after it has been magnetized during the operation of the motor 200, even when the applied external magnetic field is relatively small. The unit of remanence of an electromagnetic magnet is T. The permanent magnet 212 is made of permanent magnet material. After being saturated magnetized, the permanent magnet material can maintain stable magnetism for a long time even after the external magnetic field is removed. This helps to establish a constant magnetic field in the air gap, thereby affecting the operating stability and efficiency of the motor 200.

[0080] In this embodiment of the application, by limiting the remanence Br of the permanent magnet 212, the stacking thickness T of the stator 100, and the numerical relationship between the inner diameter D1 and the outer diameter D2 of the stator 100, and by making T, Br, D1 and D2 satisfy the relationship 35≤T×Br×D1 / D2≤40, it is possible to ensure that the motor 200 using the stator 100 has a high torque, and to ensure the rationality of the electromagnetic load of the motor 200, thereby improving the torque output capability of the motor 200.

[0081] like Figures 1 to 6 As shown, in some embodiments, T, D1, and D2 optionally satisfy the following relationship: 0.25 ≤ T × D1 / (D2) 2 ≤0.35.

[0082] In this embodiment of the application, by further limiting the stacking thickness T of the stator 100 and the dimensions of the inner diameter D1 and outer diameter D2 of the stator 100, the stacking thickness T, inner diameter D1, and outer diameter D2 of the stator 100 are made to satisfy 0.25≤T×D1 / (D2). 2 The relationship ≤0.35 allows for the design of the stator 100 dimensions without considering the residual magnetism of the permanent magnet 212, ensuring the rationality of the electromagnetic load of the motor 200 and improving the torque output capability of the motor 200.

[0083] like Figures 1 to 6 As shown, in some embodiments, optionally, the maximum distance from the axis O of the stator 100 to the bottom surface 141 of the stator slot 140 is d, where d, h, D1 and Br satisfy the following relationship: (2×d-D1)Br / h≥7.

[0084] In this embodiment, the maximum distance from the axis O of the stator 100 to the bottom surface 141 of the stator slot 140 is defined as d. The thickness h of the stator yoke 110, the inner diameter D1 of the stator 100, and the remanence of the permanent magnet 212 are limited. The relationship between d, h, D1, and Br is limited to (2×d-D1)Br / h≥7. This can improve the magnetic saturation of the stator yoke 110, further improve the rationality of the electromagnetic load of the stator 100, and further improve the torque output capability of the motor 200 using the stator 100 of this application.

[0085] like Figures 1 to 6 As shown, in some embodiments, optionally, the bottom surface 141 of the stator slot 140 includes a first arc segment 1411, a second arc segment 1412 and a planar segment 1413, wherein, in the circumferential direction of the stator 100, the planar segment 1413 is located between the first arc segment 1411 and the second arc segment 1412.

[0086] In this embodiment, the bottom surface 141 of the stator slot 140 is designed as a three-segment structure, wherein the bottom surface 141 includes a first arcuate segment 1411, a second arcuate segment 1412, and a planar segment 1413 located between the first arcuate segment 1411 and the second arcuate segment 1412. In the circumferential direction of the stator 100, the first arcuate segment 1411 and the second arcuate segment 1412 are located on both sides of the planar segment 1413.

[0087] Specifically, the first arc segment 1411 and the second arc segment 1412 are positioned close to the stator teeth 120 at both ends of the stator slot 140. When the stator teeth 120 are wound, this helps to improve the full slot ratio of the winding and makes the winding of the stator 100 more neat. Furthermore, by setting the bottom of the slot between the first arc segment 1411 and the second arc segment 1412 as a flat segment 1413, the magnetic saturation of the stator yoke 110 can be further improved.

[0088] In this embodiment of the application, by designing the bottom surface 141 of the stator slot 140 as a three-segment structure and setting the planar segment 1413 between the first arc segment 1411 and the second arc segment 1412, the winding fullness and winding neatness of the stator 100 can be improved, and the magnetic saturation of the stator yoke 110 can be improved.

[0089] like Figures 1 to 6 As shown, in some embodiments, optionally, the number Z of stator slots 140 is 12 to 48, the number of poles of rotor 210 is P, and the value of Z / P ranges from 6 / 5 to 3 / 2.

[0090] In this embodiment, the number Z of stator slots 140 in stator 100 is limited to 12 to 48, and the ratio of the number Z of stator slots 140 to the number P of rotor 210 is limited to 6 / 5 to 3 / 2. This can improve the magnetic saturation of stator 100 and improve the torque output capability of motor 200 using stator 100 of this application.

[0091] For example, the number of stator slots 140 is Z=15, the number of poles is P=10, and Z / P is 3 / 2.

[0092] For example, the number of stator slots 140 is Z=24, the number of poles is P=20, and Z / P is 6 / 5.

[0093] Figure 7 The following are schematic diagrams of the rotor core structure provided in some embodiments of this application, such as... Figure 1 , Figure 2 and Figure 7 As shown, in some embodiments, optionally, there are multiple permanent magnets 212, and the multiple permanent magnets 212 are distributed at intervals along the circumference of the rotor core 211.

[0094] The rotor core 211 has multiple grooves 213 on its surface, and a groove 213 is provided between any two adjacent permanent magnets 212; or the rotor core 211 has multiple limiting protrusions 214 on its periphery, and a limiting protrusion 214 is provided between any two adjacent permanent magnets 212.

[0095] In this embodiment, the rotor 210 is a surface-mount rotor 210, and multiple permanent magnets 212 are all disposed on the periphery of the rotor core 211 in a bonded manner, with any two adjacent permanent magnets 212 spaced apart on the periphery of the rotor core 211. Specifically, the multiple permanent magnets 212 are evenly distributed on the periphery of the rotor core 211.

[0096] like Figure 1As shown, in some embodiments, the rotor core 211 has multiple grooves 213 on its periphery, and the grooves 213 are located between two adjacent permanent magnets 212, that is, at least one groove 213 is provided between any two adjacent permanent magnets 212. The grooves 213 can increase the surface area of ​​the rotor core 211, forming airflow channels on the surface of the rotor core 211, which can effectively improve the cooling effect of the rotor core 211. In addition, the grooves 213 can also optimize the magnetic circuit distribution of the rotor 210, which helps to reduce the harmonics generated by the rotor core 211 during operation, reduce the noise generated by the motor 200, and also reduce the material usage and weight of the rotor core 211, thus saving costs.

[0097] like Figure 2 and Figure 7 As shown, in some embodiments, a plurality of limiting protrusions 214 are provided on the periphery of the rotor core 211, and the limiting protrusions 214 are located between two adjacent permanent magnets 212, that is, at least one limiting protrusion 214 is provided between any two adjacent permanent magnets 212. The limiting protrusions 214 can limit the permanent magnets 212 attached to the rotor core 211 in the circumferential direction, improve the stability of the permanent magnets 212 on the rotor core 211, and thus improve the stability of the motor 200 operation.

[0098] like Figure 7 As shown, a limiting groove is formed between two adjacent limiting protrusions 214, and the permanent magnet 212 is fitted into the limiting groove. The permanent magnet 212 is limited by the two adjacent limiting protrusions 214 in the circumferential direction of the rotor core 211. Figure 7 Arrow C in the figure indicates the circumferential direction of rotor core 211.

[0099] The following description, in conjunction with original examples and comparative examples from related technologies, and Embodiments 1, 2, 3, and 4 of this application, will be used for illustration:

[0100] The original examples in the related technologies are as follows:

[0101] The stator outer diameter D2 is 92mm, the stator inner diameter D1 is 46mm, and the numerical relationship between D1 and D2 is: D1 / D2=0.5.

[0102] The number of stator slots, Z, is 12. The maximum distance d between the bottom surface of the stator slot and the stator axis is 37.47 mm. The thickness h of the stator yoke is 8.53 mm, and the width t of the stator teeth is 8 mm. The numerical relationship between t, h, Z, and D1 is as follows:

[0103] t / h = 0.938, and Z×t / (π×D1) = 0.664.

[0104] The stator stack thickness T is 34.45 mm, the remanence Br of the permanent magnet is 1.38 T, and the numerical relationship between D1, D2 and T is: T × D1 / (D2). 2 =0.187, and T, Br, D1 and D2 satisfy; T×Br×D1 / D2=23.77.

[0105] The numerical relationship between D1, d, h and Br is: (2×d-D1)Br / h=4.68.

[0106] As can be seen, the original example in the related technology uses a small crack ratio and a decrease in the amount of permanent magnets. However, in order to meet sufficient torque output and control the degree of local saturation, the stator outer diameter and the amount of copper used are increased. Therefore, the cost of the motor increases and the cost-effectiveness is low.

[0107] The comparative examples in the relevant technologies are as follows:

[0108] The stator outer diameter D2 is 86.4 mm, and the stator inner diameter D1 is 44.4 mm. The numerical relationship between D1 and D2 is: D1 / D2 = 0.514.

[0109] The number of stator slots, Z, is 12. The maximum distance d between the bottom surface of the stator slot and the stator axis is 36.3 mm. The thickness h of the stator yoke is 6.9 mm, and the width t of the stator teeth is 7.5 mm. The numerical relationships between t, h, Z, and D1 are as follows:

[0110] t / h = 1.087, and Z×t / (π×D1) = 0.645.

[0111] The stator stack thickness T is 34.45 mm, the remanence Br of the permanent magnet is 1.38 T, and the numerical relationship between D1, D2 and T is: T × D1 / (D2). 2 =0.205, and T, Br, D1 and D2 satisfy; T×Br×D1 / D2=24.43.

[0112] The numerical relationship between D1, d, h and Br is: (2×d-D1)Br / h=5.64.

[0113] The specific embodiment of this application is as follows:

[0114] The stator outer diameter D2 is 85mm, the stator inner diameter D1 is 50mm, and the numerical relationship between D1 and D2 is: 0.576≤D1 / D2=0.588≤0.60.

[0115] The number of stator slots, Z, is 12. The maximum distance d between the bottom surface of the stator slot and the stator axis is 37.7 mm. The thickness h of the stator yoke is 5 mm, and h = D² / 2 - d. The width t of the stator teeth is 8 mm. The numerical relationships between t, h, Z, and D1 are as follows:

[0116] 1.5≤t / h=1.6≤1.7, and 0.58≤Z×t / (π×D1)=0.611≤0.63.

[0117] The stator stack thickness T is 45mm, the remanence Br of the permanent magnet is 1.38T, and the numerical relationship between D1, D2 and T is: 0.25≤T×D1 / (D2) 2 =0.311≤0.35, and T, Br, D1 and D2 satisfy; 35≤T×Br×D1 / D2=36.53≤40.

[0118] The numerical relationship between D1, d, h and Br is: (2×d-D1)Br / h=7.01≥7.

[0119] The rotor has P poles, Z / P = 3 / 2, and the rotor adopts a surface-mount structure.

[0120] The second embodiment of this application is as follows:

[0121] The stator outer diameter D2 is 85mm, the stator inner diameter D1 is 50mm, and the numerical relationship between D1 and D2 is: 0.576≤D1 / D2=0.588≤0.60.

[0122] The number of stator slots, Z, is 12. The maximum distance d between the bottom surface of the stator slot and the stator axis is 37.55 mm. The thickness h of the stator yoke is 4.95 mm, and h = D² / 2 - d. The width t of the stator teeth is 7.6 mm. The numerical relationships between t, h, Z, and D1 are as follows:

[0123] 1.5≤t / h=1.535≤1.7, and 0.58≤Z×t / (π×D1)=0.581≤0.63.

[0124] The stator stack thickness T is 47mm, the remanence Br of the permanent magnet is 1.42T, and the numerical relationship between D1, D2 and T is: 0.25≤T×D1 / (D2) 2 =0.325≤0.35, and T, Br, D1 and D2 satisfy; 35≤T×Br×D1 / D2=39.26≤40.

[0125] The numerical relationship between D1, d, h and Br is: (2×d-D1)Br / h=7.20≥7.

[0126] The specific embodiment three of this application is as follows:

[0127] The stator outer diameter D2 is 85mm, the stator inner diameter D1 is 50mm, and the numerical relationship between D1 and D2 is: 0.576≤D1 / D2=0.588≤0.60.

[0128] The number of stator slots, Z, is 12. The maximum distance d between the bottom surface of the stator slot and the stator axis is 37.55 mm. The thickness h of the stator yoke is 4.95 mm, and h = D² / 2 - d. The width t of the stator teeth is 7.6 mm. The numerical relationships between t, h, Z, and D1 are as follows:

[0129] 1.5≤t / h=1.535≤1.7, and 0.58≤Z×t / (π×D1)=0.581≤0.63.

[0130] The stator stack thickness T is 47mm, the remanence Br of the permanent magnet is 1.42T, and the numerical relationship between D1, D2 and T is: 0.25≤T×D1 / (D2) 2 =0.325≤0.35, and T, Br, D1 and D2 satisfy; 35≤T×Br×D1 / D2=39.26≤40.

[0131] The numerical relationship between D1, d, h and Br is: (2×d-D1)Br / h=7.20≥7.

[0132] The pole shoe adopts a multi-segment structure, including a first pole shoe surface, a second pole shoe surface, and a third pole shoe surface. The second pole shoe surface is located between the first pole shoe surface and the third pole shoe surface. The second pole shoe surface is a circular arc structure with a diameter equal to the inner diameter D1 of the stator. The distance between the first pole shoe surface and the third pole shoe surface and the center of the circle is greater than or equal to D1.

[0133] The fourth embodiment of this application is as follows:

[0134] The stator outer diameter D2 is 85mm, the stator inner diameter D1 is 50mm, and the numerical relationship between D1 and D2 is: 0.576≤D1 / D2=0.588≤0.60.

[0135] The number of stator slots, Z, is 12. The maximum distance d between the bottom surface of the stator slot and the stator axis is 37.55 mm. The thickness h of the stator yoke is 5 mm, and h = D² / 2 - d. The width t of the stator teeth is 8 mm. The numerical relationships between t, h, Z, and D1 are as follows:

[0136] 1.5≤t / h=1.6≤1.7, and 0.58≤Z×t / (π×D1)=0.611≤0.63.

[0137] The stator stack thickness T is 45mm, the remanence Br of the permanent magnet is 1.38T, and the numerical relationship between D1, D2 and T is: 0.25≤T×D1 / (D2) 2 =0.311≤0.35, and T, Br, D1 and D2 satisfy; 35≤T×Br×D1 / D2=36.53≤40.

[0138] The numerical relationship between D1, d, h and Br is: (2×d-D1)Br / h=7.01≥7.

[0139] The rotor is provided with a mounting groove, and the permanent magnet is set inside the mounting groove. At least part of the permanent magnet is located in the mounting groove, that is, the permanent magnet is set on the rotor in a way that is partially embedded. The rotor provides better circumferential restraint on the permanent magnet, which helps the rotor to run at high speed inside the stator.

[0140] like Figure 9 As shown, compared with the original examples and comparative examples in the related art, the maximum torque of the motor is increased and the cost is reduced in Embodiments 1, 2, 3 and 4 of this application, which improves the cost performance of the motor. That is, under the same temperature rise conditions, the maximum torque output capability of the motor in the embodiments of this application is better than that of the original examples and comparative examples in the related art, and the cost performance is higher.

[0141] Figure 8 The following are schematic diagrams of the vehicle structure provided in some embodiments of this application, such as... Figure 8 As shown, an electric power steering system 300 according to some embodiments of this application is applied to a vehicle 400. The electric power steering system includes an electric motor 200 as described in any of the above embodiments, and therefore has all the beneficial effects of the electric motor as described in any of the above embodiments, which will not be described one by one here.

[0142] In this application, the term "multiple" refers to two or more unless otherwise expressly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0143] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. The above descriptions are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An electric motor, characterized in that, include: A rotor, the rotor comprising a rotor core and permanent magnets, at least a portion of the permanent magnets being attached to the outer surface of the rotor core; The stator is sleeved on the circumference of the rotor. The stator includes a stator yoke and a plurality of stator teeth. The plurality of stator teeth are distributed circumferentially along the stator yoke. One end of each stator tooth is connected to the stator yoke, and the other end of the stator tooth extends radially along the stator. Wherein, the thickness of the stator yoke is h in the radial direction of the stator, and the width of the stator tooth is t in the circumferential direction of the stator, and h and t satisfy the following relationship: 1.5≤t / h≤1.

7.

2. The electric motor according to claim 1, characterized in that, The stator yoke portion and two adjacent stator teeth portion enclose a stator slot, the number of stator slots being Z, and the stator further includes: The pole shoe is connected to the other end of the stator tooth portion; The distance from the axis of the stator to the pole shoe is D1, and Z, D1 and t satisfy the following relationship: 0.58≤Z×t / (π×D1)≤0.

63.

3. The electric motor according to claim 2, characterized in that, The distance from the axis of the stator to the outer side of the stator yoke is D2, and the outer side is the side away from the stator teeth. D1 and D2 satisfy the following relationship: 0.576≤D1 / D2≤0.

60.

4. The electric motor according to claim 3, characterized in that, The stator has a stack thickness of T, and the remanence of the permanent magnet is Br. T, Br, D1, and D2 satisfy the following relationship: 35 ≤ T × Br × D1 / D2 ≤ 40.

5. The electric motor according to claim 4, characterized in that, T, D1, and D2 satisfy the following relationship: 0.25 ≤ T × D1 / (D2) 2 ≤0.

35.

6. The electric motor according to claim 4, characterized in that, The maximum distance from the axis of the stator to the bottom surface of the stator slot is d, where d, h, D1 and Br satisfy the following relationship: (2×d-D1)Br / h≥7.

7. The electric motor according to any one of claims 2 to 6, characterized in that, The bottom surface of the stator slot includes a first arc segment, a second arc segment, and a planar segment, wherein, in the circumferential direction of the stator, the planar segment is located between the first arc segment and the second arc segment.

8. The electric motor according to any one of claims 2 to 6, characterized in that, The number of stator slots Z is 12 to 48, the number of rotor poles is P, and the value of Z / P ranges from 6 / 5 to 3 / 2.

9. The electric motor according to any one of claims 1 to 6, characterized in that, The number of permanent magnets is multiple, and the multiple permanent magnets are distributed at intervals along the circumference of the rotor core; The rotor core has multiple grooves on its periphery, and the grooves are provided between any two adjacent permanent magnets; or the rotor core has multiple limiting protrusions on its periphery, and the limiting protrusions are provided between any two adjacent permanent magnets.

10. An electric power steering system, characterized in that, The electric power steering system, used in vehicles, includes: The electric motor as described in any one of claims 1 to 9.

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